NSMutbleArray - 添加/删除具有属性的对象 - 泄漏答案

【问题标题】：NSMutbleArray - add/remove objects with properties - leaksNSMutbleArray - 添加/删除具有属性的对象 - 泄漏
【发布时间】：2011-04-16 17:54:41
【问题描述】：

我的应用程序存在泄漏问题。

我正在尝试向 NSMutableArray 添加和删除对象。

这里是 Demande 类：

@interface Demande : NSObject { 
//attibuts de la classe demande
NSString *demId;
NSString *demStatut;
NSString *demTitle;
NSString *demCreated;
NSString *demIdCopro;
NSString *demIdImmeuble;
NSString *demIdLot;
NSString *demDescriptif;
NSString *demAuteur;
NSString *demIdAuteur;
NSString *demLoginAuteur;   
}
@property (retain,nonatomic) NSString *demId;
@property (retain,nonatomic) NSString *demIdCopro;
@property (retain,nonatomic) NSString *demIdImmeuble;    
@property (retain,nonatomic) NSString *demIdLot;
@property (retain,nonatomic) NSString *demDescriptif;
@property (retain,nonatomic) NSString *demStatut;
@property (retain,nonatomic) NSString *demTitle;
@property (retain,nonatomic) NSString *demCreated;
@property (retain,nonatomic) NSString *demAuteur;
@property (retain,nonatomic) NSString *demIdAuteur;
@property (retain,nonatomic) NSString *demLoginAuteur; 
@end


#import "Demande.h"
@implementation Demande

@synthesize demId,demIdCopro,demIdImmeuble,demIdLot,demDescriptif,demStatut,demTitle,demCreated,demAuteur,demIdAuteur,demLoginAuteur;

- (void)dealloc {   

[demId release];
[demIdCopro release];
[demId release];
[demIdImmeuble release];
[demIdLot release];
[demDescriptif release];
[demStatut release];
[demTitle release];
[demCreated release];
[demAuteur release];
[demIdAuteur release];
[demLoginAuteur release];    
[super dealloc];

}
@end

我在 MyTableViewController 中尝试做什么：

@interface MyTableViewController : UITableViewController {

IBOutlet UITableView *tableV;
NSMutableArray *tab_Demandes;   
}
@end

@implementation MyTableViewController

- (void)requestDReloadDone:(ASIHTTPRequest *)request
{   

NSData *responseData = [request responseData];  

NSString *jsonString = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
//NSLog(@"JSON: %@",jsonString);

NSDictionary *results = [jsonString JSONValue];

NSArray *demandes = [results objectForKey:@"Demandes"]; 

    [tab_Demandes removeAllObjects]; // -------- CRASH HERE !!!, except the first time through the method  because the array is empty  

    for (NSDictionary *demandeD in demandes)
{

    //parse du JSON
    NSString *titre = [demandeD objectForKey:@"Title"];
    NSString *desriptif = [demandeD objectForKey:@"Description"];
    NSString *Id = [demandeD objectForKey:@"Id"];
    NSString *created = [demandeD objectForKey:@"Created"];
    NSString *statut = [demandeD objectForKey:@"Statut"];
    NSString *copropriete = [demandeD objectForKey:@"Copropriete"];
    NSString *immeuble = [demandeD objectForKey:@"Immeuble"];
    NSString *lot = [demandeD objectForKey:@"Lot"];
    NSString *auteur = [demandeD objectForKey:@"Author"];
    NSString *auteurId = [demandeD objectForKey:@"IdAuthor"];
    NSString *auteurLogin = [demandeD objectForKey:@"Login"];

    //Creation de l'objet
    Demande *dem =[[Demande alloc] init];       
    dem.demTitle=titre;
    dem.demId=Id;
    dem.demCreated=created;

    NSString *descriptifDecode = [desriptif stringByReplacingPercentEscapesUsingEncoding:
                                  NSASCIIStringEncoding];       

    dem.demDescriptif=descriptifDecode;
    dem.demIdCopro=copropriete;
    dem.demIdImmeuble=immeuble;
    dem.demIdLot=lot;
    dem.demStatut=statut;
    dem.demAuteur=auteur;
    dem.demIdAuteur=auteurId;
    dem.demLoginAuteur=auteurLogin;

    [tab_Demandes addObject:dem];

    [dem release];
}

[tableV reloadData];

[jsonString release];
}

在应用程序第一次启动时，我的数组 tab_Demandes 是空的，所以一切都很好 [removeAllObjects] 可以正常工作，因为其中没有对象。当我重新加载 tab_Demandes 时，我需要清除它。那是应用崩溃的时候

我意识到如果我这样做了：

- (void)dealloc {   
     /*
[demId release];
[demIdCopro release];
[demId release];
[demIdImmeuble release];
[demIdLot release];
[demDescriptif release];
[demStatut release];
[demTitle release];
[demCreated release];
[demAuteur release];
[demIdAuteur release];
[demLoginAuteur release];
     */  
[super dealloc];
}

在 Demande 类中我可以做到

[tab_Demandes removeAllObjects]

在 TableViewController 中。

但是我有每个对象需求的属性泄漏。就像当我做 [dem release] 时，属性也被释放，当我想从我的 tab_Demandes 中做 [removeAllObjects] 时，没有要释放的属性，我得到一个 Bad_Access。

如果有人有想法...

编辑：cellForROw 方法：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {    

static NSString *CellIdentifier = @"Cell";    
CustomCellViewController *cell = (CustomCellViewController *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) 
{
   // NSLog(@"Cell created");
    NSArray *topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"CustomCellViewController" owner:nil options:nil];

    for(id currentObject in topLevelObjects)
    {
        if([currentObject isKindOfClass:[CustomCellViewController class]])
        {
            cell = (CustomCellViewController *)currentObject;
            break;
        }
    }
}

    // Set up the cell...   

    cell.lbl_demId.text=[NSString stringWithFormat:@"%@", [[tab_Demandes objectAtIndex:indexPath.row ] demId]]; 
    cell.lbl_demCopro .text=[NSString stringWithFormat:@"%@", [[tab_Demandes objectAtIndex:indexPath.row] demIdCopro ]];
    cell.lbl_demImmeuble.text=[NSString stringWithFormat:@"%@", [[tab_Demandes objectAtIndex:indexPath.row] demIdImmeuble]];
    cell.lbl_demLot.text=[NSString stringWithFormat:@"%@", [[tab_Demandes objectAtIndex:indexPath.row] demIdLot]];
    cell.lbl_demDescriptif.text=[NSString stringWithFormat:@"%@", [[tab_Demandes objectAtIndex:indexPath.row] demTitle]];
    if ([[[tab_Demandes objectAtIndex:indexPath.row] demStatut] isEqualToString: @"Validée"])
    {
    cell.lbl_ImageView.image=[UIImage imageNamed:@"VDEM2.png"];
    }
    if([[[tab_Demandes objectAtIndex:indexPath.row] demStatut] isEqualToString: @"Initiée"])
    {
       cell.lbl_ImageView.image=[UIImage imageNamed:@"IDEM.png"];
    }
    if([[[tab_Demandes objectAtIndex:indexPath.row] demStatut] isEqualToString: @"Terminée"])
    {
    cell.lbl_ImageView.image=[UIImage imageNamed:@"TDEM.png"];
    }
    if([[[tab_Demandes objectAtIndex:indexPath.row] demStatut] isEqualToString: @"En coursée"])
    {
    cell.lbl_ImageView.image=[UIImage imageNamed:@"EDEM.png"];

    }

return cell;       
}

【问题讨论】：

你有没有尝试过非原子，保留而不是保留，非原子。我知道这听起来很傻，但以防万一......
嘿，VdesmedT ;-)。我尝试了非原子，保留，没有改变任何东西。将 dem 对象添加到 tab_Demandes 后是否需要立即释放它们？这是正确的方法吗？当我释放对象时，对象属性是否被释放？
tab_Demandes 只有指向 dem 对象的指针。如果我做 dem 释放，也许如果属性被释放，当我尝试做 removeAllObjects 时，指针可能仍在引用已经发布的属性？
如果您不知道下次何时需要这些对象，您应该释放它们，因为数组将保留它自己的副本。
数组为自己保留对象？那么为什么它不能删除对象呢？

标签： iphone objective-c xcode memory-leaks nsmutablearray

【解决方案1】：

tab_Demandes 在哪里被初始化？

仅在.h文件中声明是不够的，还必须告诉编译器分配和初始化。

一个简单的解决方法可能是将[tab_Demandes removeAllObjects]; 替换为

if(!tab_Demandes) { // tab_Demandes is nil and has not previously been created
    tab_Demandes = [[NSMutableArray arrayWithCapacity:10] retain];
} else {
    [tab_Demandes removeAllObjects];
}

不要忘记在您的 dealloc 方法中使用 [tab_Demandes release]

【讨论】：